Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
  • A61B18/1492—Probes or electrodes therefor having a flexible, catheter-like structure, e.g. for heart ablation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/02—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by cooling, e.g. cryogenic techniques
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M25/00—Catheters; Hollow probes
  • A61M25/01—Introducing, guiding, advancing, emplacing or holding catheters
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00005—Cooling or heating of the probe or tissue immediately surrounding the probe
  • A61B2018/00011—Cooling or heating of the probe or tissue immediately surrounding the probe with fluids
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00005—Cooling or heating of the probe or tissue immediately surrounding the probe
  • A61B2018/00011—Cooling or heating of the probe or tissue immediately surrounding the probe with fluids
  • A61B2018/00029—Cooling or heating of the probe or tissue immediately surrounding the probe with fluids open
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
  • A61B2018/1405—Electrodes having a specific shape
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
  • A61B2018/1472—Probes or electrodes therefor for use with liquid electrolyte, e.g. virtual electrodes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B2218/00—Details of surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2218/001—Details of surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body having means for irrigation and/or aspiration of substances to and/or from the surgical site
  • A61B2218/002—Irrigation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M25/00—Catheters; Hollow probes
  • A61M25/0067—Catheters; Hollow probes characterised by the distal end, e.g. tips
  • A61M25/0068—Static characteristics of the catheter tip, e.g. shape, atraumatic tip, curved tip or tip structure
  • A61M25/007—Side holes, e.g. their profiles or arrangements; Provisions to keep side holes unblocked
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing

Definitions

• This application relates generally to medical devices and, more particularly, to systems and methods related to open-irrigated ablation catheters.
• thrombus blood clot
• Some ablation catheter systems have been designed to cool the electrode and surrounding tissue.
• open- irrigated catheter systems pump a cooling fluid, such as a saline solution, through a lumen in the body of the catheter, out through the ablation electrode, and into surrounding tissue.
• the cooling fluid cools the ablation electrode and surrounding tissue, thus reducing the likelihood of a thrombus, preventing or reducing impedance rise of tissue in contact with the electrode tip, and increasing energy transfer to the tissue because of the lower tissue impedance.
• An embodiment of an open-irrigated ablation catheter system comprises a catheter body, a generally hollow electrode tip body, and a distal insert.
• the catheter body has a fluid lumen.
• the electrode tip body has a closed distal end and an open proximal end for connection to the catheter body.
• the electrode tip body has a plurality of irrigation ports to enable fluid to exit from the electrode tip body.
• the distal insert is positioned in the electrode tip body to define a proximal fluid chamber and a distal fluid chamber in the electrode tip body.
• the distal insert has a fluid conduit between the proximal fluid chamber and the distal fluid chamber.
• the plurality of irrigation ports enable fluid to exit from the distal fluid chamber.
• FIG. IA illustrates an open-irrigated catheter electrode tip with near laminar flow of cooling fluid at the exit ports; and FIG. IB illustrates an open- irrigated catheter electrode tip designed to cause the cooling fluid to exit the electrode with a turbulent flow.
• FIG. 2 illustrates an ablation electrode designed to promote turbulent flow, according to an embodiment of the present subject matter.
• FIG. 4 illustrates an electrode tip embodiment with a distal insert illustrated therein.
• FIG. 5A-5B illustrate planar and cross-sectional views of an embodiment of a distal insert.
• FIGS. 6A-6D illustrate a process for manufacturing the electrode, according to various embodiments, and further illustrate the turbulent flow generated by the electrode design.
• the cooling fluid within this electrode tends to cool the tissue at the distal end as represented by the cooled area 104, and toward the proximal end, as represented by the cooled area 105.
• the near laminar flow of cooling fluid 102 from the irrigation ports 103 tends to cause the cooling fluid to flow away from the ablation electrode and the tissue near the ablation site, potentially causing uneven cooling and localized hot spots along the ablation electrode.
• FIG. IB illustrates an open-irrigated catheter electrode tip 106 designed to cause the cooling fluid to exit the electrode with a turbulent flow 107.
• the figure illustrates a cross sectional view around the electrode tip, and does not illustrate cooling jets outside of the plane of the figure.
• the turbulence around the body of the electrode tip 106 encourages a more uniform cooling of the electrode body, and also encourages the dilution of the blood in the vicinity of the ablation electrode.
• the risk of thrombus formation significantly decreases using turbulent flow of cooling fluid to both dilute the blood near the electrode and uniformly cool the electrode.
• the ablation electrode 208 includes a proximal chamber 213 and a distal chamber 214 separated by a distal insert 215.
• the distal insert 215 includes a fluid conduit 216 connecting the proximal and distal chambers, and further includes an opening to receive the thermocouple 212, allowing a distal end of the thermocouple to be positioned in the distal chamber 214.
• Exit or irrigation ports 217 provide openings through which the cooling fluid flows from the distal chamber 214 to the outside of the ablation electrode 208.
• the turbulence increases as the coolant exits through the irrigation ports in the tip electrode.
• the edges of the irrigation ports are purposely left rough and ragged.
• the distal end 218 of the distal chamber is a relatively flat wall to further encourage the laminar flow of the pressurized fluid as it flows through the fluid conduit in the distal tip insert. The combination of these factors causes the fluid exiting the coolant port to create turbulence around the entire electrode body, encouraging a more uniform cooling of the electrode body and the dilution of the blood in the vicinity of the ablation electrode.
• the arrangement of the irrigation ports with respect to the distal chamber encourages the fluid to flow out at an angle toward the proximal end of the ablation electrode to cause the cooling fluid to flow, in a turbulent manner, at the proximal end of the electrode as well as at the distal end of the electrode.
• FIGS. 3A-D illustrate various views of an ablation electrode tip, according to various embodiments.
• the illustrated electrode tip 308 has six irrigation ports 317 equally spaced around the circumference of the electrode tip, such that each port is approximately 60 degrees away from the adjacent ports.
• the present subject matter is not limited to equally-spaced irrigation ports or to a particular number of irrigation ports.
• the system can be designed with other numbers and arrangements of irrigation ports.
• FIG. 3 A illustrates the electrode tip 308 at a first rotational position with respect to an axis of rotation 319
• FIG. 3B illustrates the electrode tip 308 at a second rotational position with respect to the axis 319, wherein the second rotational position is approximately 30 degrees from the first rotational position.
• FIG. 3 C illustrates a view from a proximal end of the electrode tip
• FIG. 3D illustrates a cross-sectional view of the electrode tip taken along line A-A in FIG. 3C.
• FIG. 4 illustrates an electrode tip embodiment 408 with a distal insert 415 illustrated therein.
• the illustrated electrode 408 includes a generally flat distal end 418.
• the illustrated electrode 408 also includes a proximal portion 421 and a distal portion 422.
• the distal portion 422 has a generally cylindrical configuration with a first diameter
• the proximal portion 421 has a generally cylindrical configuration with a second diameter reduced from the first diameter.
• the distal insert, the distal fluid chamber, and the proximal fluid chamber are within the distal portion of the electrode.
• the irrigation ports 417 are on the distal portion 422.
• the illustrated distal insert includes a fluid conduit 416 extending between the proximal and distal chambers, and further includes a thermocouple opening 420 configured to receive a thermocouple to allow a distal end of the thermocouple to be placed in the distal chamber of the electrode 408.
• FIG. 5 A illustrates a planar view of the distal insert 515
• FIG. 5B illustrates a cross-sectional view of the distal insert. These views further illustrate the fluid conduit 516 and the thermocouple opening 520 formed in the distal insert.
• the edges of the irrigation ports are intended to be rough. By way of example, the edges are not machined smooth after the ports are formed.
• the hollow tip body has an open interior region defined by an exterior wall of the tip section. In the illustrated embodiment, the hollow tip body has a generally cylindrical shape.
• the distal end 618 is generally flat (e.g. a slight curvature) with rounded edges 640.
• FIG. 6B illustrates a cross-sectional view of the electrode tip after the distal insert 615 is placed inside the electrode tip.
• the distal insert 615 is positioned against the rough edges of the irrigation ports 617.
• an embodiment of the electrode tip body has a diameter on the order of about 0.08-0.1 inches, has a length on the order of about 0.2-0.3 inches, and has an exterior wall with a thickness on the order of 0.003-0.004 inches.
• the distal insert 615 has a diameter corresponding to the interior diameter of the electrode tip.
• the distal insert has a diameter of approximately 0.08 inches and a width of approximately 0.06 inches.
• the fluid conduit 616 has a diameter between approximately 0.015 to 0.020 inches.
• the thermocouple opening 620 is sized to receive a thermocouple. In the illustrated embodiment, the thermocouple opening is approximately 0.02 inches.
• the tip section 102 is formed from a conductive material. For example, some embodiments use a platinum-iridium alloy. Some embodiments use an alloy with approximately 90% platinum and 10% iridium. This conductive material is used to conduct RF energy used to form legions during the ablation procedure.
• a plurality of irrigation ports 617 or exit ports are shown near the distal end of the tip section. By way of example and not limitation, an embodiment has irrigation ports with a diameter approximately within a range of 0.01 to 0.02 inches.
• the irrigation portions have a width (represented by the diameter of the ports of approximately 0.01 to approximately 0.02) to height (represented by the wall thickness of the electrode tip body of approximately 0.003 to approximately 0.004) ratio between about 2 to 7.
• This ratio may be referred to as an aspect ratio of the irrigation ports. Larger aspect ratios in comparison to small aspect ratios promote more turbulent flow.
• the irrigation ports 617 are formed approximately 0.30 to 0.45 inches from the distal end of the electrode tip.
• the distal end 618 is generally flat. For example, in an embodiment in which the outer diameter of the electrode is approximately 0.09 inches, the curvature of the relatively flat distal portion 618 has a radius of approximately 0.29 inches.
• the radius of the edges 640 at the distal end is approximately 0.02 inches.
• Fluid such as a saline solution, flows through these ports 617 to the exterior of the electrode. This fluid is used to cool the ablation electrode tip and the tissue near the electrode. This temperature control reduces coagulum formation on the tip of the catheter, prevents impedance rise of tissue in contact with the catheter tip, and increases energy transfer to the tissue because of the lower tissue impedance.
• FIG. 6C illustrates the electrode after the proximal portion 621 of the electrode tip is swaged.
• the length of the distal portion is approximately 0.15 to 0.17 inches. In some embodiments, the length of the distal portion is between 0.155 to 0.160 inches.
• the proximal portion has a length, in some embodiments, of approximately 0.06 to 0.08 inches. In some embodiments, the length of the proximal portion is between 0.070 to 0.075 inches. In the illustrated embodiment, the diameter of the distal portion is approximately 0.09 inches and the diameter of the proximal portion is approximately 0.07 to 0.08 inches.
• FIG. 6D illustrates a cooling lumen 611 of the catheter, after the electrode is connected to the catheter body 626.
• the cooling lumen 611 of the catheter may have a diameter of, by way of example, 0.02 to 0.04 inches, which corresponds to a cross-sectional area of about 0.0006 in 2 to about 0.003 in 2 .
• Various catheter embodiments include more than one lumen.
• some catheter embodiments have a dual lumen structure, where the structure has two side-by-side channels.
• the diameter of each lumen in one dual lumen structure embodiment is approximately 0.019 inches, where the combination of lumens provide a total cross-sectional area of about 0.0011 in 2 (about 0.00057 in 2 for each lumen).
• FIG. 6D further illustrates fluid flowing through the cooling lumen into the proximal chamber 613.
• the diameter of the fluid passage expands significantly from the cooling lumen 611 (e.g. 0.03 inches) to the inner diameter of the proximal chamber (e.g. 0.08 inches).
• the diameter of the fluid passage retracts significantly from the proximal chamber (e.g. 0.09 inches) to the fluid conduit 616 (0.018 inches) of the distal insert.
• the length of the proximal fluid chamber 613 is approximately 0.06 inches, corresponding to the width of the digital insert.
• the diameter of the fluid passage expands again from the fluid conduit 616 (e.g. 0.018 inches) to the inner diameter of the distal chamber (e.g. 0.08 inches), which further encourages the pressurized fluid to circulate or mix.
• the length of the distal fluid chamber 614 is approximately 0.04 inches. Additionally, the pressurized fluid deflects off of the distal wall of the electrode to further mix the fluid, and to cause the fluid to exit out of the irrigation ports 617 toward the proximal end of the electrode.
• the mixing of the pressurized fluid within the electrode changes the laminar flow of the fluid within the cooling lumen 611 of the catheter into a turbulent flow, represented at 607, as the fluid exits the irrigation ports.
• the irrigation portions are relatively large (diameter of approximately 0.017 inches), and the electrode walls of the irrigation ports are relatively thin (e.g. 0.003 inches). This geometry, in addition to the rough edges of the irrigation portions, further encourages the turbulent nature of the fluid flow as it exits the distal chamber.
• the geometry of the proximal chamber 613, the distal chamber 614, the fluid conduit 616, and the irrigation ports 617 can be adjusted to change the fluid flow characteristics of the pressurized fluid as it exits the irrigation ports.
• FIG. 7 illustrates an embodiment of a mapping and ablation system 723, wherein the system includes an open-irrigated catheter that promotes turbulent flow, according to various embodiments of the present subject matter.
• the illustrated catheter includes an ablation tip 724 with an RF ablation electrode 725 and irrigation ports therein.
• the catheter can be functionally divided into four regions: the operative distal ablation electrode 725, a main catheter region 726, a deflectable catheter region 727, and a proximal catheter handle region where a handle assembly 728 including a handle is attached.
• a body of the catheter includes a cooling fluid lumen and may include other tubular element(s) to provide the desired functionality to the catheter.
• the addition of metal in the form of a braided mesh layer sandwiched in between layers of plastic tubing may be used to increase the rotational stiffness of the catheter.
• the deflectable catheter region 727 allows the catheter to be steered through the vasculature of the patient and allows the probe assembly to be accurately placed adjacent the targeted tissue region.
• a steering wire (not shown) may be slidably disposed within the catheter body.
• the handle assembly may include a steering member to push and pull the steering wire. Pulling the steering wire causes the wire to move proximally relative to the catheter body which, in turn, tensions the steering wire, thus pulling and bending the catheter deflectable region into an arc. Pushing the steering wire causes the steering wire to move distally relative to the catheter body which, in turn, relaxes the steering wire, thus allowing the catheter to return toward its form.
• the deflectable catheter region may be made of a lower durometer plastic than the main catheter region.
• the illustrated system 723 includes an RF generator 729 used to generate the energy for the ablation procedure.
• the RF generator 729 includes a source 730 for the RF energy and a controller 731 for controlling the timing and the level of the RF energy delivered through the ablation tip 724.
• the illustrated system 723 also includes a fluid reservoir and pump 732 for pumping cooling fluid, such as a saline, through the catheter and out through the irrigation ports.
• Some system embodiments incorporate a mapping function. Mapping electrodes may be incorporated into the catheter system. In such systems, a mapping signal processor 733 is connected to the mapping electrodes to detect electrical activity of the heart.
• This electrical activity is evaluated to analyze an arrhythmia and to determine where to deliver the ablation energy as a therapy for the arrhythmia.
• modules and other circuitry shown and described herein can be implemented using software, hardware, and/or firmware.
• Various disclosed methods may be implemented as a set of instructions contained on a computer-accessible medium capable of directing a processor to perform the respective method.
• an open-irrigated ablation catheter system comprises: a catheter body with a fluid lumen therein; a generally hollow electrode tip body with a closed distal end and an open proximal end for connection to the catheter body, wherein the electrode tip body has a plurality of irrigation ports to enable fluid to exit from the electrode tip body; and a distal insert positioned in the electrode tip body to define a proximal fluid chamber and a distal fluid chamber in the electrode tip body.
• the distal insert has a fluid conduit between the proximal fluid chamber and the distal fluid chamber.
• the plurality of irrigation ports enable fluid to exit from the distal fluid chamber.
• a second system embodiment includes the system according to system embodiment 1, wherein the irrigation ports have rough edges.
• a third system embodiment includes the system according to any of the system embodiments 1-2, wherein the electrode tip body has a
• the irrigation ports are approximately equally spaced about the circumference of the electrode tip body.
• a fourth system embodiment includes the system according to any of the system embodiments 1-3, wherein the irrigation ports are proximate to the distal insert to enable fluid to exit the distal fluid chamber near the distal insert toward a proximal end of the distal fluid chamber.
• a fifth system embodiment includes the system according to any of the system embodiments 1-4, wherein: the electrode tip body has a proximal portion and a distal portion; the distal portion includes the distal fluid chamber, the proximal fluid chamber, and the distal insert; and the proximal portion is swaged to a reduced diameter with respect to the distal portion.
• a sixth system embodiment includes the system according to any of the system embodiments 1-5, wherein: each of the fluid lumen, the proximal fluid chamber, the fluid conduit, and the distal fluid chamber have a diameter; the diameter of the proximal fluid chamber is larger than the diameter of the fluid lumen; the diameter of the fluid conduit is smaller than the diameter of the proximal fluid chamber; and the diameter of the distal fluid chamber is larger than the diameter of the fluid conduit.
• a seventh system embodiment includes the system according to any of the system embodiments 1-6, wherein: the proximal fluid chamber has a diameter of approximately 0.08 inches and a length of approximately 0.06; the fluid conduit has a diameter of approximately 0.018 inches and a length of approximately 0.06 inches; and the distal fluid chamber has a diameter of approximately 0.08 inches and a length of approximately 0.04 inches.
• An eighth system embodiment includes the system according to any of the system embodiments 1-7, wherein the electrode tip body has an exterior wall with a thickness of approximately 0.003-0.004 inches. Each irrigation port is formed in the exterior wall, and each irrigation port has a diameter of approximately 0.01 to 0.02 inches.
• a ninth system embodiment includes the system according to any of the system embodiments 1-8, wherein six irrigation ports are approximately equally spaced about a circumference of the electrode tip body.
• a tenth system embodiment includes the system according to any of the system embodiments 1 -9, where the system further comprises a fluid reservoir configured to deliver pressurized cooling fluid through the fluid lumen in the catheter body to the electrode tip body.
• An eleventh system embodiment includes the system according to any of the system embodiments 1-10, wherein the system further comprises a radio frequency (RF) generator electrically connected to the electrode tip body to deliver RF ablation energy from the electrode tip body.
• RF radio frequency
• a method for forming an open-irrigated ablation electrode tip comprises: forming a generally cylindrical electrode tip body, wherein a distal end of the electrode tip body is a closed end and a proximal end of the electrode tip body is an open end; forming irrigation ports around a circumference of the electrode tip body proximate to the distal end of the electrode tip body, wherein the irrigation ports allow fluid to flow out from within the electrode tip body; placing a distal insert in the generally cylindrical tip body, wherein a distal fluid chamber reservoir is defined by the distal insert and the electrode tip body, and the distal fluid chamber is between the distal end of the electrode tip body and the distal insert; and connecting the electrode tip body to a catheter body, wherein a proximal fluid chamber is defined by the distal insert and the electrode tip body, wherein the distal insert includes a fluid conduit extending between the proximal fluid chamber to the distal fluid chamber.
• a second method of formation embodiment includes the method according to the method of formation embodiment 1, wherein forming the generally cylindrical electrode tip body includes drawing the electrode tip body.
• a third method of formation embodiment includes the method according to the method of formation embodiment 1, wherein forming irrigation portions includes drilling irrigation ports, and leaving the irrigation ports rough.
• a fourth method of formation embodiment includes the method according to the method of formation embodiment 1 , wherein forming irrigation ports includes performing a spark EDM (electric discharge machining) process to form the irrigation ports, and leaving the irrigation ports rough.
• a spark EDM electric discharge machining
• a fifth method of formation embodiment includes the method according to any of the method of formation embodiments 1-4, wherein forming irrigation ports includes spacing the irrigation ports approximately equally around a circumference of the electrode tip body.
• a method for cooling an open-irrigated ablation electrode comprises: delivering pressurized fluid from a fluid lumen of a catheter body into an ablation electrode, wherein fluid flow in the fluid lumen is generally laminar; transforming the generally laminar fluid flow from the fluid lumen into a turbulent fluid flow within the ablation electrode; and delivering the pressurized fluid with turbulent fluid flow through irrigation ports of the ablation electrode.
• a second method of operating embodiment includes the method according to the method of operating embodiment 1, wherein transforming the generally laminar fluid flow into the turbulent fluid flow includes: receiving the pressurized fluid from the fluid lumen of the catheter body into a proximal fluid chamber, wherein a diameter of the proximal fluid chamber is larger than a diameter of the fluid lumen; receiving the pressurized fluid from the proximal fluid chamber into a fluid conduit, wherein a diameter of the fluid conduit is smaller than a diameter of the proximal fluid chamber; and receiving the pressurized fluid from the fluid conduit into a distal fluid chamber, wherein a diameter of the distal fluid chamber is larger than the diameter of the fluid conduit.
• a third method of operating embodiment includes the method according to any of the method of operating embodiments 1-2, wherein delivering generally turbulent fluid through irrigation ports includes delivering fluid through irrigation ports that are not machined smooth after the irrigation ports are formed.
• a fourth method of operating embodiment includes the method according to any of the method of operating embodiments 1-3, wherein delivering generally turbulent fluid through irrigation ports includes directing fluid flow out from the electrode and toward a proximal end of the electrode.

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• 2010
  • 2010-07-12 EP EP10731914A patent/EP2453821A1/en not_active Withdrawn
  • 2010-07-12 US US12/834,265 patent/US20110009857A1/en not_active Abandoned
  • 2010-07-12 JP JP2012520696A patent/JP2012532737A/ja active Pending
  • 2010-07-12 CA CA2768454A patent/CA2768454A1/en not_active Abandoned
  • 2010-07-12 KR KR1020127003775A patent/KR101379647B1/ko not_active IP Right Cessation
  • 2010-07-12 WO PCT/US2010/041677 patent/WO2011008681A1/en active Application Filing

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